Safety door latch mechanism



July 22, 1969 F. J. MOORE 3,456,974

SAFETY DOOR LATCH MECHANISM Filed June 9, 1967 2 Sheets-Sheet 1 .FIEZZFIZZ-T E Paw/75$ MOORE Ivan/er:

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United States Patent Cfiice 3,456,974 Patented July 22, 1969 US. Cl.292359 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to adoor latch mechanism arranged for insertion through the width of a doorto control and actuate a latch member inserted through the edg of thedoor. The latch member is frusto conical in shape receivable into afrusto conical latch receiving element on the door frame. The operativeportion of the latch includes a first tubular member having a notchedperiphery to engage with the latch device and includes interiorlythereof a cam mechanism extending longitudinally there through withmeans for actuating the same on either end thereof. The camming rodincludes a first locking device engageable to prevent rotation of thetubular actuating member with a camming device for shifting this lockdevice from locked position from the other end of the tubular member.The entire operating mechanism is carried by the first tubularlongitudinal member to permit installation into a door with a minimumaperture being necessary for the door.

In the past various door latch mechanisms have been provided whichbasically depend upon a one way situation. This is to say that the doorlatch mechanism itself is tapered in one general direction such thatwhen the door is closed into the door frame the camming surface willforce the latch inwardly to permit the latch to pass along a door framemounted guiding unit into the door latch receptacle. This system issubject to tampering in that it is only necessary to Celluloid the doorlatch in order to force it into retracted position and then open thedoor. Applicants design of a frusto-conical latching mechanism willforce any material against the side surface thereof to bend and beforced into the frusto-conical recessed portion thereof rather than topermit urging of the latch rearwardly into open position.

It is a further object of applicants invention to provide a cam lockingmechanism for doors which includes a simplified camming device whereby amanual locking device is provided on one side of the door for push-pulloperation and a cylinder lock is provided on the other side of the doorsuch that the door may be opened from the cylinder side thereof and maybe either locked or opened from the manual operated side thereof.

It is still a further object of applicants invention to provide asimplified door lock and latching construction which will utilize arelatively small area of the door for mounting the same therein andwhich permits the mounting of all actuating and actuated portionsthereof within a relatively small area.

These and other objects and advantages of my invention will more fullyappear from the following description made in connection with theaccompanying drawings, wherein like reference characters refer to thesame or similar parts throughout the several views, and in which:

FIG. 1 is a partial side elevation of a typical installation of a doorlatch embodying applicants concept illustrated with a door and doorframe;

FIG. 2 is a horizontal section taken substantially along line 2-2 ofFIG. 1 illustrating the door latch in closed and locked position;

FIG. 3 is a vertical section taken substantially along line 33 of FIG.2;

FIG. 4 is a detailed illustration of the carnming portions of thelocking mechanism;

FIG. 5 is a vertical section taken substantially along line 55 of FIG.2;

FIG. 6 is a vertical section taken substantially along line 6-6 of FIG.5 particularly illustrating the dead locking device incorporated inapplicants invention; and

FIG. 7 is a horizontal view taken substantially along lines 7-7 of FIG.5 illustrating the dead locking feature incorporating applicants device.

In accordance with the accompanying drawings applicants door lock deviceis mounted in a door D by providing a first mounting passage Ptherethrough and a second passage T extending inwardly from the edge ofthe door to intersect with the mounting passage P. These are the onlyapertures which must be provided through a door to positively mountapplicants device therein and it should be noted initially that the sizeof each of these apertures is relatively small when compared with thosedoor latch devices which are known in the prior art. In order toaccommodate this unit into a door frame F the standard door stop S isprovided and likewise a door latch receptacle generally designated R isprovided to the door frame structure. The receptacle R in the form shownincludes a substantially flat plate member 11 having a frusto-conicalshaped recess 12 centrally thereof and having a guiding lip 13 on thereceiving edge thereof to permit a door latch to normally be receivedand cammed into the plate 11 while passing over the lip section 13 andthence downwardly by spring pressure to be received into thefrustoconical shaped recess 12. This door latch receiving mechanismexcept for the frusto-conical shaped portion 12 will be generally knownto those skilled in the art.

The door latching mechanism generally designated 14 includes a generallycylindrical latch portion 15 having a frusto-conical end portion 15a tobe received into recess 12 and is followed by a shoulder portion 151;reduced in diameter from the normal cylindrical portion thereof toprovide a shoulder against which a pressure spring 16 may operate. Ahousing member 17 is provided to be received within passage T and has ashoulder portion 17a on the inner end thereof for agreeing abutment withcompressible spring member 16 such that the spring 16 will be compressedbetween shoulder 15b and shoulder 17a. This inner end of housing 17 isalso provided with a passage 17b therethrough to permit a linkage member18 to pass therethrough into the operative and operational section ofthe mechanism. Linkage member 18 is provided with a loop 18:: on theinner end thereof for engagement with an actuating pin member 19 whilethe latch connective end 18b of link 18 is received into a slot on latchmember 15 and a pin 15d is designed to pass therethrough for positiveconnection of the link 18 to the latch member 15 and thus the latch 15to the operative pin member 19. It should be obvious that along thelength of this link 18 there must be a free lost-motion section suchthat when the latch member 15 is forced inwardly as by abutment with theplate 13 upon closing the door the operative pin 19 will not cause thedoor knobs to rotate.

The operative section of the mechanism is generally designated 20 andincludes a first tubular latch actuating section 21 mounted for rotativemovement within passage P on a pair of flange elements 22-23 whichflanges are arranged on respective sides of the door D. Flange element23 is provided with a longitudinally extending rim portion 24 which asillustrated in FIG. 6 is provided with a pair of diametrically opposedlongitudinally arranged locking slot members 25-25 having divergingguide-in surfaces 25a on the outwardly extending end thereof. A pair ofcover plates designated respectively 26-27 are provided to normallyoverlie and cover the journaling members 22-23 and the outwardlyextending portions thereof 26a-27a are likewise provided of a propershape to serve as a proper journaling surface for the tubular latchactuating member 21.

A first actuating knob 28 is provided in fixed relation to the tubularactuator 21 through a longitudinally extending flange portion 28a and apasasge 28b is provided completely therethrough for the mounting of whatis commonly known as a cylinder lock 29 therein. This cylinder lock 29as commonly known provides a stationary stop 29a and a rotatable barrel31 which barrel 31 is connected to the lock unit 29 through anadditional pin 31a. This barrel member 31 is guided within the tubularactuating structure 21 through an inwardly projecting radial flange 32and the end 31b of this barrel structure 31 is provided with a pair ofguide slots 31c arranged in diametrically opposed position for housingand guiding a pinned connective rod and cam carrying element 33 therein.In the form shown the cam carrying rod element 33 is provided forslideable movement within a central aperture of the hollow barrel 31 bya radially extending pin 33a received into slot 310 to permit limitedoscillation of the rod 33 therein. The opposite end 3317 of rod 33extends longitudinally through the tubular actuating shaft 21 forslideable engagement internally of a locking rod designated 35. Rod andcam carrying member 33 also carries a beveled cam 34 intermediate theends thereof which cam 34 is a single plane cam as particularlyillustrated in FIG. 3 with its actuating camming surface arranged inopposed relation to the cylinder lock 29.

Locking rod 35 includes a generally tubular rod member arranged forslideable movement over the extending end 3311 of the rod and cammingmember 33 and is provided with a cylindrical boss 36 on the inward endthereof arranged for longitudinal sliding with tubular structure 21. Apair of pins 3737 are arranged in radially extending, diametricallyopposed relation on the enlarged cylindrical portion 36 and the tubularmember 21 is provided with a pair of diametrically opposed slots 21a-21ato permit the cylindrical block to be received therein and slidelongitudinally therewithin. Extending pins 37 are arranged to meet withthe receiving locking slots 25 on rim 24 when in their innermost orlocking location.

A second cam follower 38 is provided on the enlarged cylindrical portion36 and extends longitudinally parallely up to the camming rod member 33to normally abut with the cam device 34 for operation thereagainst.Locking rod 35 extends outwardly through the end of the tubularstructure 21 and through a second actuating knob member 40. A capturingelement 41 may be threadably received into the end of locking rod 35.Knob 40 is removably received upon the tubular actuating member 21 andthis may be accomplished through set screws or the like which may passthrough a cylindrical flange portion 40a arranged generally centrally ofthe knob 40. As illustrated in FIGS. 2 and 3 a passage 4% is formed inthe outward extending end of the knob to permit the locking bar 35 topass therethrough.

As illustrated in FIG. 2 an arcuate passage 21b is defined in aperipheral surface of tubular actuating member 21 to permit the link 18to pass internally into the tubular member 21 and be fastened to anoperating pin member 19. Pin member 19 is fixedly attached to the innerwall of the tubular member 21 such that when the tubular member 21 isrotated the shifting of pin member 19 will pull the link 18 inwardlythus pulling the latch member 15 into the housing 17 against thepressure of spring 16.

Operation of the device to this point should be clearly understood whenthe locks are not being utilized. This is to say that either of theknobs 28 or 40 when rotated will rotate the attached tubular actuatingmember 21 and thence the attached pin 19 to pull inwardly on the link 18thus retracting the latch member 15. The lost motion connection in link18 will also permit the latch 15 to be pushed into retracted positionwithout rotation of either 4 of the knobs such as when the door is swunginto closed position.

Operation of the lock device which consists basically of the locking rod35, cam carrying rod 33 and the cylinder lock 29 with its associatedtubular structure 21 is as follows. When it is required to lock the doorit is necessary to actuate the lock from the inside or the push pullside of lock rod 35. Normally of course the cylinder lock 29 will bearranged outside of the area to be locked. Upon pushing rod 35 inwardlythe pins 37 will be received into the locking slots 25 on flange 24 asillustrated in FIG. 6. This of course will prevent rotation of the knobsand the attached tubular member as the pins 37 pass not only into thelocking slot 25 but likewise are arranged in slots 2112 within thetubular structure. When it is desired to unlock the door from the insideit is only necessary to pull the locking pin rod 35 outwardly to releasethe pins 37 from their respective locking slots 25. When it is desiredto unlock the door from the outside or cylinder side of the door and thepins 37 are in their normal locking slots 25, insertion of the properkey into cylinder lock 29 will permit rotation of the cylinder lock 29and thence will provide rotation of the barrel member 31 and cam 34 androd 33 will be rotated as particularly illustrated in FIG. 4. Rotationof this cam 34 will, as illustrated in FIG. 4 drive the cam follower 38longitudinally therealong and will drive the pin members 37 from thelocking slots 25. The locking pins 37 again being guided for suchlongitudinal movement by the passages 21a. Complete rotation of thecylinder lock 29 to permit retraction of the key will return the camsurface 34 to its normal position which will again permit the lock rod35 to be pushed into closing position.

A dead locking device is also provided with this unit and thisparticular device is illustrated in FIGS. 5, 6 and 7. As illustrated inthese figures, an additional aperture 45 is provided withinlongitudinally extending flange 24 and an aperture 21b is provided inthe actuating tubular portion 21. These apertures are in normallyaligned position when the tubular actuator 21 is in its normal positionwith the latch extending outwardly. A locking rod device 46 is providedto extend through the cover plate 27 and particularly through anaperture 27a therein. This aperture 27a is a key shaped aperture suchthat it is possible to retract the rod 46 and shift the same along theperiphery of the cover plate 27 to maintain the rod in an upwarddirection without removing the locking end thereof from the aperture 45in the longitudinal flange 24. A stop member 46a may be provided toprevent complete removal of this pin 46 and a small hand graspingportion 46b may be provided on the end thereof to assist in lifting andlocating this positive locking unit. This locking unit is completelyindependent of the other locking portions of the device and as such mayactually serve as a dead bolt type lock in that even if the key isutilized in the outside of the door this lock member 46 will preventrotation of the tubular member 21 and thus maintain the latch 15 in itsextended position.

It should be obvious that applicant has provided a new and unique simplesystem for providing a locking mechanism for door latches which issimple in construction and positive in its operation. Likewise the lockprovided herein is a dual safety lock mechanism in that the shape of thelatch prevents slipping of the latch and the dead lock combination willpermit positive locking of the unit, against even key opening.

It will, of course, be understood that various changes may be made inthe form, details, arrangements and proportion of parts withoutdeparting from the scope of the invention, which generally statedconsists in the matter 0 set forth in the appended claims.

What is claimed is:

1. A door latch unit including:

(a) a latch retaining section arranged to be received into the edge of adoor having a latching element slidably arranged therein;

(b) a tubular rotatable actuating member mounted for rotation throughthe width of the door having an access slot formed through the peripherythereof arranged to be aligned With said latching element;

(c) means connecting said latching element to said actuating member forretraction of said element upon rotation of said actuating member; I

(d) a flange secured to one side of the door and having at least oneslot therein extending longitudinally with said actuating member;

(e) said actuating member having at least one longitudinal extendingslot therein arranged to be aligned with said slot in said flange;

(f) a locking rod longitudinally 'slidable from one end of and withrespect to said actuating member having means thereon to commonly engageboth of said slots to prevent rotation of said actuating member andhaving a passage formed longitudinally therein;

(g) a camming rod extending from the other end of and with respect tosaid actuating member and telescoping with said locking rod to positionthe same in cam responsive position when said locking rod engages bothof said slots; said locking rod having a longitudinally extending memberthereon to engage with the camming surface of said camming rod foractuation thereby;

(h) handle means on the respective ends of said actuating member.

2. The structure set forth in claim 1 wherein said locking rod isarranged internally of said actuating member with at least one radiallyextending pin thereon for engagement with both of said slots.

3. The structure set forth in claim 1 and a key lock member arranged onthe end of the actuating member opposite said locking rod receiving endand telescoping with said camming rod for actuation thereof whilepermitting longitudinal movement of said camming rod and locking rod.

References Cited UNITED STATES PATENTS 127,027 5/1872 Clark 2921752,727,773 12/1955 Hagstrom 292-l69 3,228,218 1/1966 Wilson 70146 MARVINA. CHAMPION, Primary Examiner ROBERT L. WOLFE, Assistant Examiner US.Cl. X.R. 70146, 216

